The investment seeks to track the investment results of the Markit iBoxx USD Liquid Investment Grade Index composed of U.S. dollar-denominated, investment-grade corporate bonds. The fund generally invests at least 90% of its assets in securities of the underlying index and at least 95% of its assets in investment-grade corporate bonds. The underlying index is designed to provide a broad representation of the U.S. dollar-denominated liquid investment-grade corporate bond market.